[flake8-type-checking] Avoid false positives for | in TC008

[Daverball]

This is a follow-up to #15180

Summary

| is not a valid runtime operation between types pre Python 3.10, so we should avoid unquoting the type expression.

Additionally most type checkers don't care about the execution context, so while they will allow | between types in stub files for convenience, they will still disallow it in type checking blocks, since those are treated as regular runtime code.

Test Plan

cargo nextest run

[github-actions]

ruff-ecosystem results

Linter (stable)

✅ ecosystem check detected no linter changes.

Linter (preview)

ℹ️ ecosystem check detected linter changes. (+0 -2 violations, +0 -0 fixes in 1 projects; 54 projects unchanged)

apache/airflow (+0 -2 violations, +0 -0 fixes)

ruff check --no-cache --exit-zero --ignore RUF9 --no-fix --output-format concise --preview --select ALL

- airflow/decorators/condition.py:32:35: TC008 [*] Remove quotes from type alias
- airflow/decorators/condition.py:33:35: TC008 [*] Remove quotes from type alias

Changes by rule (1 rules affected)

code	total	+ violation	- violation	+ fix	- fix
TC008	2	0	2	0	0

[MichaReiser]

Reviewing this PR is a bit challenging right now because it's based on #15180 and I can't change the base because your an external contributor. I suggest we wait with reviewing until the base PR is merged. Please ping us if we happen to forget to review the PR after #15180 is merged.

[Daverball]

@MichaReiser @AlexWaygood You should be able to review this now

[Daverball]

The ecosystem results make sense to me now. Since airflow targets Python 3.9+ mypy would flag those type aliases if they were unquoted. So a TC008 shouldn't trigger, despite there being no runtime effects.